The present invention relates generally to methods and apparatuses for cleaning the crankcase of an internal combustion engine by means of flushing the crankcase to remove dirt and sediment therefrom, and more particularly to an apparatus and method for cleaning an engine of the type having an oil filter mounting assembly wherein an internal bypass valve permits circulating oil to bypass the mounted oil filter.
It is the general practice in maintaining a four-cycle internal combustion engine to change the oil and filter periodically by draining the crankcase, replacing the oil filter, and refilling the crankcase with clean oil. However, this practice does not remove all the sludge and contaminants that build up in an engine crankcase over time, thereby adversely affecting engine operating efficiency and decreasing engine life. Accordingly, the preferred method of cleaning an internal combustion engine is to perform a crankcase flushing operation, which cleans engine components and removes sludge and contaminants from the crankcase.
Known apparatuses and methods for flushing engines either require expensive equipment and complicated procedures, or do not achieve satisfactory results. For instance, one known method of flushing an engine crankcase involves replacing the oil in the crankcase with a suitable flushing liquid while keeping the dirty oil filter for use during the flushing operation. One problem with this method is that the flushing liquid passes through the dirty filter and carries contaminants throughout the engine where they may remain after completion of the flushing operation. Furthermore, the oil filter, already dirty, may become clogged further and prevent easy passage of the flushing liquid therethrough.
Another known method of flushing engines is directed to overcoming the disadvantages associated with using a dirty filter during flushing and involves replacing the dirty filter with a clean filter for the purpose of flushing the engine. After the flushing operation is completed, the clean filter is dirty and must be replaced before adding the new oil. Therefore, this method requires the use of two new filters, as well as the mess and inconvenience of having to remove two dirty filters.
A further apparatus and method for flushing an internal combustion engine is shown and described in U.S. Pat. No. 4,174,231, issued to H. Hobgood. This patent discloses the use of a hollow adaptor device which replaces an oil filter and allows the flushing fluid to flow therethrough unfiltered. One disadvantage of this device and method is the mess and inconvenience associated with having to dispense of the cleaning liquid trapped in the hollow device. Furthermore, the adaptor is structurally similar to an ordinary oil filter and, as such, would be equally expensive.
The present invention is directed to overcoming the problems and disadvantages of the above-described prior art methods and apparatuses for cleaning internal combustion engines by flushing.